Batch anneal with or w/o mandrel

[Sweetsoap]

Hi there,
I have a newbie question for the group. I want to batch anneal my beads and was wondering if I should do this with or without the mandrel? I read somewhere that you should remove it but no reason was given.
Thanks so much,
Karen

[NLC Beads]

I did it without just because they were easier to load in the kiln that way. Also, if you only have a set number of mandrels, you can keep making beads until you have a full kiln-load.

[Sweetsoap]

Thanks for your response. I should have added that I was concerned that the kiln wash may stick to the beads. Do you set the beads directly on the shelf or do you set them on the blanket?

[alexm]

You can do it either way. Don't worry about the kiln wash sticking to the beads, you are not getting the beads hot enough for that to happen. I would only put the beads directly on the floor of the kiln if you have applied kiln wash to it. That way if the kiln temperature should spike too high, the floor of the kiln will not be ruined by the molten glass. You can also put the beads on a blanket or in a glass dish. I often use a Pyrex dish when I batch anneal for others.

[theglasszone]

I batch anneal - I remove the mandrels before putting into the kiln - my door wouldn't shut if I didn't.

One tip I can give - and it's helped me immensely, is to not "soak" your beads in water to remove the mandrels - I use Sludge Plus (Arrow Springs) and double dip the mandrels. The thickness of the release, coupled with it's great formula, allows me to simply turn the bead on the mandrel when it's cooled, after first breaking away the release that bumps up right against the bead. The bead easily slips off the mandrel at this point, and into the kiln it goes. I never clean the release out of the bead, either - before it's annealed. I think this alleviates a lot of stress being put on it before it's annealed and when it's most vulnerable.

Hope that helps you out a bit!
DeAnne in CA

[theglasszone]

...wanted to add that I sometimes (but not always - just with big beads or Silver Glasses) place a layer of Fusing Shelf Paper (Delphi) on to the kiln floor and place the beads atop it to insure an "insulation" between the bead and kiln shelf.

DeAnne in CA

[cadia]

I take all my beads off their mandrels , then thread them onto clean mandrels to anneal on as many mandrel as it takes, kinda like a shish-ka -bob ~ but making sure none of the beads touch one another, lay them across the kiln diagonally, fit any strays into the free space W/ O mandrels ( also not touching). I can fit many beads into the kiln this way.

[moonkat]

I batch-anneal my beads at times. I take them off the mandrels. I have 2 rod racks that fit in my kiln just perfectly. I face the 2 racks toward each other, put all my beads on clean mandrels (with a bit of space between each bead) and rack them up. I very rarely have breakage and have never had a meltdown.

[margiek19380]

What are you doing with the beads after you are happy with their look and BEFORE you put them into the annealer? As a glass blower I was always taught to get the piece into the annealer ASAP...

Right now my wife and I are just cooling them for as long as we can stand to leave them between the fiber blankets. Then we put them into water to soak. I like the comment above about double dipping the mandrel and just being able to slip the bead off.

Has anyone here built a mailbox annealer?
thanks
david and margie

[bluecatbeads]

I read some where else on the threads that someone just puts them into a terra cotta pot and anneals them this way... I am guessing this is very wrong to do also...

[prairieson]

Originally Posted by bluecatbeads

I read some where else on the threads that someone just puts them into a terra cotta pot and anneals them this way... I am guessing this is very wrong to do also...

Some folks also use pyrex dishes as well. Nothing wrong with it at all.

The only reason to suspend, support, or contain work while batch annealing is to protect the kiln floor should the kiln get too hot. A proper batch annealing cycle should never get the kiln hot enough to leave kiln marks or deform the work.

[prairieson]

Originally Posted by margiek19380

As a glass blower I was always taught to get the piece into the annealer ASAP...

Larger blown work won't survive without going into the kiln immediately... larger masses of glass will almost insure death by thermal shock.

Originally Posted by margiek19380

Has anyone here built a mailbox annealer?
thanks
david and margie

Ed Slawson makes an awesome mailbox kiln, I'm not sure if he markets them or not though.

[simvet02]

I take my beads off the mandrels and then when I batch anneal them I use the mandrels again to string them between two kiln posts.

Another tip I can give you was something that I had to do, if you use silver glasses that have been reduced, mine lost the reduction in my kiln. There wasn't enough oxygen in my kiln and the silvers were reabsorbed into the glass
I had to add charcoal to the kiln. I go the charcoal from the aquarium department at Walmart. Works like a charm. I add it to every batch now.

[cadia]

Jan !
How much charcoal, what is this doing?
Would this keep terra from losing it's color or is that just a temperature thing?
Is it safe to keep charcoal in the kiln for all firings?
Does it get "used up"?
And thanks in advance for answering all my questions!!
After stringing my beads on clean mandrels I just lay them on the kiln floor that has fiber blanket on it.

[simvet02]

Sally,I use a tablespoon. The charcoal is putting the oxygen back in the atmosphere of the kiln. They are so tightly sealed that they have no oxygen and the reduced glass tends to loose its metal. The metal is reabsorbed into the surface of the glass.

I have left some of the unused charcoal in the kiln for normal glass firings and it didn't hurt. If you are going to use a glass that reduces in the kiln you will want the charcoal. Some kilns don't have this problem. But my first batch anneal was so disappointing because all of the silver reduced areas were gone.

[prairieson]

Originally Posted by simvet02

The charcoal is putting the oxygen back in the atmosphere of the kiln. They are so tightly sealed that they have no oxygen and the reduced glass tends to loose its metal. The metal is reabsorbed into the surface of the glass.

Just the opposite is true. Reduction takes place in an oxygen poor environment. The metal oxides in the glass "give up" oxygen and the metals are left behind on the surface. If your reduction goes away in the kiln it indicates the kiln has an oxygen rich environment, and the metals on the surface recombine with the oxygen to return to the oxide state again. Adding charcoal robs the kiln atmosphere of oxygen, creating a reduction environment and preventing that from happening.

[Ro]

thanks for the charcoal info! to make a more oxy environment ive heard to leave the door cracked open
ro

[Sweetsoap]

WOW!!! Excellent thread and so much great information.
Thanks to everyone for your input.
This helps me so much. I have taught ceramics and have slumped glass. I am now going to be trying bead making and can't wait.
My first class is on Monday and I can barely sleep at night thinking about it.
This group is very knowledgeable. I know I will have more questions in the future. Actually, I have another one but I am trying to find the information without posting.
Thanks again.
Karen

[simvet02]

I knew it was one environment or the other. Trying to keep them all straight. Thanks for clearning that up. All I know is that I need to put the charcoal in every time I batch anneal to keep any reduction.

Is there a danger of it doing th opposite to other glasses?

[lunamoonshadow]

Ed Slawson's kilns are AWESOME!

Nikki anneals my beads when I make beads @ home & I'm a weirdo--I actually dremel them out before I send them to her--I figure if they survive the dremel *and* the post office, then the annealling, they should really be stable!

~luna